D-ring/tie down installation on an insulated garage floor

Whatever you decide to install, make sure they are attached to something other than the floor. You'll need to attach them to crossmembers, frame, something like that. If you don't, they will pull out eventually.

If its just not possible to do that, then use a large and thick metal backing plate under the floor. Not as good, but lots better than just screwing a tie-down to a wood floor.